Because of a similarity in deficits seen in alcoholics and patients with damage to the right hemisphere, it has been hypothesized that right-brain functions, visuospatial, and emotional functions in particular, are more vulnerable to the effects of alcoholism than are left-brain functions. Studies of people with brain lesions have provided evidence that disruption of the integrity of the corpus callosum can contribute to right hemisphere functional decline as well as diminution of interhemispheric (cross-callosal) transfer ability accompanying bilateral cortical atrophy (impairment in sensory and cognitive integration [Fabri et al 2001] and interhemispheric transmission [Brown et al 2000; Curran et al 2001]). Diffusely distributed bilateral cortical atrophy and thinning of the corpus callosum might be interpreted as a selective right hemisphere functional deficit using conventional neuropsychological tests because (a) right hemisphere functions may have less cortical representation than left hemisphere functions (possibly because left hemisphere functions are used more frequently), or (b) The absence of prefrontal activity of the alcoholics for emotional faces is striking. bilateral damage could cause an interhemispheric collaboration dysfunction (eg, excessive interhemispheric inhibition or a cross-callosal transfer dysfunction), which affects visuospatial and emotional functions more than linguistic functions.
